| Agriculture is a basic industry which influences the development of our country's economy. However, in the process of planting a large number of crops are often plagued by diseases and pests, which limited the rapid development of China's economy. In order to solve this problem, scientists have developed many pesticides which is similar to dichlorvos, malathion, dimethoate, chlorpyrifos. They has made a great achievements on suppressing pest blooms to minimize the extent of damage to crops. However, in the growth process with crops or after maturing they can not be completely break down, a lot of pesticides in different types of agricultural products and fruits and vegetables skin are left in different levels. Therefore, pesticide residue has become a major threat to human health. Therefore, it is more and more important to study a method that can effectively degrade pesticide residues in agricultural products.As a new technology of high pressure pulse degradation pesticide is an efficient, economic and non polluting method. In this paper, we study the effects of pulsed electric field on the four kinds of organ phosphorus pesticides (dichlorvos, malathion, dimethoate, chlorpyrifos) molecules of chemical bond and use Materials Studio software to simulate applying electrostatic field for the four kinds of organic phosphorus pesticide molecular,and analysis the change of molecular chemical bond length and internal energy. According to the interaction between electromagnetic field and dielectric, deduce the relationship between pulsed electric field and electrostatic field, and obtain the pulse electric field of four kinds of organ phosphorus pesticide degradation principle and the energy when chemical bonds are breaking and corresponding for pulse electric field optimization parameters (pulse strength, duration, pulse number), build a stochastic models between the three parameters of the electric field pulse and the bond energy. After the experiment has been proved. This discovery provides a basis for the degradation of organ phosphorus pesticides in micro theory. Its main research contents are as follows:1) the theory of electromagnetic field and the theory of dielectric are introduced briefly and build the relationship between the point electric field and the applied electric field E= (1+?e) E0;2) Analyse the relationship between the electromagnetic field and the organic phosphorus pesticide, including the calculation of the electric field in the presence of pesticides;3) in this paper introduce molecular dynamics simulation principle briefly, using materials Studio software to build the structure model of dichlorvos? malathion? dimethoate and chlorpyrifos, meanwhile analyse the effect on four kinds of organic phosphorus pesticide with electrostatic field, namely with the increase of the applied electric field, organic phosphorus pesticide chemical bond length increases, the P-O, P-S and C-N, C-S are the most prominent, compared with other chemical bond such as C-H and O-H more prone to breakage. It is also because these chemical bonds are easy to break, it gives us a lot of support for the study of pesticide degradation.4) by GC combined with experimental verification through the pulse high voltage of dichlorvos, malathion, dimethoate and chlorpyrifos degradation product and by molecular simulation software analysis agree with material generated by the breaking of chemical bonds. And provides a powerful theoretical support for the future of the high voltage pulse. When the electric field strength of the static electric field reaches 0.05a.u., the chemical bond absorbs enough energy to be cut off. Through the experimental study, dichlorvos, malathion, dimethoate and chlorpyrifos degradation rate reached the maximum electric field intensity were 2866.58V/m,2889.44V/m, X1=2669.31V/m, X1=2814.63V/m is 0.0557a.u.,0.0562a.u., 0.0519a.u.,0.0547a.u.. |
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